Department of Metallurgical and Materials Engineering

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Browsing Department of Metallurgical and Materials Engineering by Author "Afolabi, A.S."

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  • Item
    Open Access
    Liquid Metallurgy Synthesis and Thermo–electrical Characterization of Copper–aluminum Metal Matrix Composite
    (Advanced Materials Research, 2013) Osoba, L.O.; Afolabi, A.S.; Emmanuel, V.; Fasuba, O.A.
    Samples of copper-aluminum reinforced metal matrix composite (MMC) were prepared by liquid metallurgy method using micron–sized silicon carbide (SiC) particulate. The resultant MMC samples were characterized to determine their thermal, electrical and mechanical properties in respect to varying particle sizes (212, 425, 710 and 1200 µm) of the SiC. The analyses of the results obtained showed that the thermal conductivity of the composite increased with decrease in particle size and volume fraction of the SiC. Also with decrease in grains size, high thermal conductivity was achieved by increasing the volume fraction. The results obtained in this study showed that alloying Cu matrix with aluminium is effective in reducing the interfacial reactions of a typical Cu-SiC matrix composite. The synthesized MMC samples also possessed a combination of high thermal and electrical conductivities with a low coefficient of thermal expansions which is synonymous to a low tensile strain at a maximum load. These properties were achieved for a 60%Cu/Al(40%SiC) at 212 µm, 50%Cu/Al(50%SiC at 12 µm and 70%Cu/Al(30%SiC) at 710 µm. The microstructural evaluation using optical microscopy (OM) indicated good dispersion of the SiC particles in all the samples which consequently enhanced the microhardness obtained in the MMC samples.
  • Item
    Open Access
    Suitability of Nigerian Rocks as Refractory Materials for Monolithic Furnace Lining
    (Particulate Science and Technology: An International Journal, 2012) Osoba, L.O.; Afolabi, A.S.
    The physical, chemical composition and service properties of imported monolithic refractory and locally produced refractory lining materials were investigated and compared in this study. The samples were compacted in a standard rammer, cured in air for 24 h and oven dried for 24 h. They were then heated to temperature of 100 C and characterized to determine their refractory properties. These samples were tested for parameters, such as bulk density, porosity, thermal conductivity, electrical conductivity, refractoriness, permeability, and cold strength. The results obtained indicate that local acidic ramming mass was found to be a good substitute to imported ramming masses due to comparative properties of the former. A fusion temperature of 1620 C was obtained in the local sample which is equivalent to the value obtained for the imported ramming masses. The results of other properties show little or no variation between the locally produced ramming mass and the imported ones.